Association between ergonomic risk exposures and insomnia symptoms: a mediation analysis of the 5th Korean working conditions survey.

BACKGROUND: This study investigates the relationship between ergonomic risk exposures and insomnia symptoms, using data representative of Korea's general working population. METHODS: Data from the 5th Korean Working Conditions Survey were used for this study. The eligible population (employees) for the current study was 37,026. Insomnia symptoms were estimated using the minimal insomnia symptom scale (MISS) questionnaire. Logistic regression analysis was conducted to explore the association between ergonomic risks and insomnia symptoms. RESULTS: All the investigated ergonomic risks increased odd ratios (ORs) for insomnia symptoms: Tiring or painful positions (OR, 1.64; 95% CI, 1.43-1.88); lifting or moving heavy loads (OR, 2.33; 95% CI, 1.99-2.71); long periods of standing (OR, 1.47; 95% CI, 1.29-1.69); and repetitive hand or arm movements (OR, 1.46; 95% CI, 1.29-1.67). The mediated proportion of musculoskeletal pain was 7.4% (95% CI, 5.81-10.13), and the mediated proportion of feeling of exhaustion was 17.5% (95% CI, 5.81-10.13). CONCLUSIONS: This study provides evidence for the relationship between ergonomic risks and insomnia symptoms, for which musculoskeletal pains and the feeling of exhaustion may be potential mediators.

Association between social jetlag and self-rated health: Evidence from Korean representative working population.

BACKGROUND: Social jetlag is a circadian misalignment that arises from a discrepancy between activity/sleep schedules on school/work days and free days. This study explored the correlation between social jetlag and self-rated health (SRH) in a representative sample of Korea. METHODS: This study included 8259 working population in the Korea National Health and Nutrition Examination Survey, 2016-2018. Social jetlag was calculated as the difference between the midpoint of sleep time on work day and work-free day. Five-point Likert scale of SRH was used to assess subjective health perception on general health conditions. Multiple logistic regression analysis was performed to calculate the odds ratios (ORs) and 95 % confidence interval (CI) for poor SRH in the 1-2 h or longer than 2 h social jetlag groups compared to that in the reference group (less than 1 h), after adjusting for age, sex, marital status, occupation, household income, and weekly working hours. RESULTS: The proportions of those with <1 h, 1-2 h, >2 h of social jetlag were 63.80 %, 25.67 %, and 10.53 %, respectively. The risk of poor SRH increased as social jetlag increased. Greater social jetlag was significantly associated with an increased likelihood of reporting poor SRH. The adjusted ORs for the groups with social jetlag between 1 and <2 h, and >2 h were 1.100 (95 % CI = 0.935-1.295), and 1.503 (95 % CI = 1.097-1.727), respectively. Moreover, the OR trend was statistically significant (p for trend = 0.008). CONCLUSION: This study found that social jetlag and poor SRH were significantly related in the Korean working population.

Working hours and the regulations for night shift workers.

There are several types of shift work in Korea: rotating shift, 24-hour shift, day-night shift, fixed night work, and.so on. As a result of analyzing the 8th Korea National Health and Nutrition Examination Survey and the 6th Korean Working Condition Survey, Korean shift workers accounted for 11.6%-13.9% of wage workers. Weekly working hours of shift workers were 57.69 ± 1.73 (24-hours shift) and 49.97 ± 0.67 (fixed night shift), which were significantly longer than day workers. To prevent health consequences of night work, many countries regulate the working hours of night work not to exceed 7-9 hours a day. However, Korea does not regulate working hours for night work, and some occupations may work more hours than the prescribed overtime hours. To prevent health consequences and reduce working hours for Korean night shift workers, it is necessary to regulate the working hours of night shift workers by law.

Development of algorithm for work intensity evaluation using excess overwork index of construction workers with real-time heart rate measurement device.

Background: The construction workers are vulnerable to fatigue due to high physical workload. This study aimed to investigate the relationship between overwork and heart rate in construction workers and propose a scheme to prevent overwork in advance. Methods: We measured the heart rates of construction workers at a construction site of a residential and commercial complex in Seoul from August to October 2021 and develop an index that monitors overwork in real-time. A total of 66 Korean workers participated in the study, wearing real-time heart rate monitoring equipment. The relative heart rate (RHR) was calculated using the minimum and maximum heart rates, and the maximum acceptable working time (MAWT) was estimated using RHR to calculate the workload. The overwork index (OI) was defined as the cumulative workload evaluated with the MAWT. An appropriate scenario line (PSL) was set as an index that can be compared to the OI to evaluate the degree of overwork in real-time. The excess overwork index (EOI) was evaluated in real-time during work performance using the difference between the OI and the PSL. The EOI value was used to perform receiver operating characteristic (ROC) curve analysis to find the optimal cut-off value for classification of overwork state. Results: Of the 60 participants analyzed, 28 (46.7%) were classified as the overwork group based on their RHR. ROC curve analysis showed that the EOI was a good predictor of overwork, with an area under the curve of 0.824. The optimal cut-off values ranged from 21.8% to 24.0% depending on the method used to determine the cut-off point. Conclusion: The EOI showed promising results as a predictive tool to assess overwork in real-time using heart rate monitoring and calculation through MAWT. Further research is needed to assess physical workload accurately and determine cut-off values across industries.

Social jetlag and risk of depression: Results from the Korea National Health and Nutrition Examination Survey.

BACKGROUND: Social jetlag, which is the mismatch between endogenous rhythm and social timing, is prevalent among the working population. Social jetlag may result in mood changes; however, evidence of relationship between social jetlag and depressive disorders has not been fully verified. Hence, this study aimed to investigate the association between social jetlag and depressive symptoms in a representative working population of South Korea. METHODS: This study included 5447 Korean employees in the Korea National Health and Nutrition Examination Survey. Social jetlag was calculated as the difference between the midpoint of sleep time on weekdays and free days. Depressive symptoms were assessed using Patient Health Questionnaire-9. Multiple logistic regression was used to estimate the odds ratio after adjusting for confounding factors. Moreover, social jetlag and continuous depression scores were evaluated using linear regression and generalized additive models. RESULTS: The proportion of the participants who had >2 h of social jetlag was 10.26 %. Depressive symptoms increased as social jetlag increased. Multiple logistic regression analysis showed that the adjusted OR (95 % confidence interval) for 1 to 2 h of social jetlag was 1.355 (0.891-2.059) and for >2 h was 1.859 (1.084-3.187), which <1 h was reference. LIMITATIONS: This study used a cross-sectional design and measurements were based on self-reported scales. CONCLUSION: This study found that social jetlag and depressive symptoms were significantly related in the Korean working population.

Real-World Study of Osimertinib in Korean Patients with Epidermal Growth Factor Receptor T790M Mutation-Positive Non-Small Cell Lung Cancer.

PURPOSE: Although osimertinib is the standard-of-care treatment of epidermal growth factor receptor (EGFR) T790M mutation-positive non-small cell lung cancer, real-world evidence on the efficacy of osimertinib is not enough to reflect the complexity of the entire course of treatment. Herein, we report on the use of osimertinib in patients with EGFR T790M mutation-positive non-small cell lung cancer who had previously received EGFR tyrosine kinase inhibitor (TKI) treatment in Korea. MATERIALS AND METHODS: Patients with confirmed EGFR T790M after disease progression of prior EGFR-TKI were enrolled and administered osimertinib 80 mg daily. The primary effectiveness outcome was progression-free survival, with time-to-treatment discontinuation, treatment and adverse effects leading to treatment discontinuation, and overall survival being the secondary endpoints. RESULTS: A total of 558 individuals were enrolled, and 55.2% had investigator-assessed responses. The median progression-free survival was 14.2 months (95% confidence interval [CI], 13.0 to 16.4), and the median time-to-treatment discontinuation was 15.0 months (95% CI, 14.1 to 15.9). The median overall survival was 36.7 months (95% CI, 30.9 to not reached). The benefit with osimertinib was consistent regardless of the age, sex, smoking history, and primary EGFR mutation subtype. However, hepatic metastases at the time of diagnosis, the presence of plasma EGFR T790M, and the shorter duration of prior EGFR-TKI treatment were poor predictors of osimertinib treatment. Ten patients (1.8%), including three with pneumonitis, had to discontinue osimertinib due to severe adverse effects. CONCLUSION: Osimertinib demonstrated its clinical effectiveness and survival benefit for EGFR T790M mutation-positive in Korean patients with no new safety signals.

Nypa fruticans Wurmb inhibits melanogenesis in isobutylmethylxanthine­treated melanoma via the PI3K/AKT/mTOR/CREB and MAPK signaling pathways.

Malignant melanoma is responsible for 3.0 and 1.7% of cases of tumor incidence and tumor-associated mortality, respectively, in the Caucasian population. Melanoma is a type of skin cancer that occurs when melanocytes mutate and divide uncontrollably. Nypa fruticans Wurmb (NF) is abundant in phytochemicals (polyphenols and flavonoids) and is traditionally used to treat diseases of the respiratory tract. The present study investigated the inhibitory effect of the ethyl acetate fraction of NF (ENF) on melanogenesis-related factors in isobutylmethylxanthine-treated B16F10 melanoma cells. Phenolics and flavonoids (caffeic acid, catechin, epicatechin and hirsutine) in ENF were analyzed via liquid chromatography-mass spectrometry. In addition, the main factors involved in melanogenesis were identified using immunoblotting, reverse transcription-polymerase chain reaction (RT-PCR), RT-quantitative PCR and immunofluorescence. ENF significantly suppressed the expression of tyrosinase (TYR) and TYR-related proteins 1 and 2 (TYRP-1/2), which are the main factors involved in melanogenesis. ENF also inhibited the expression of microphthalmia-associated transcription factor (MITF) by phosphorylating the related cell signaling proteins (protein kinase B, mammalian target of rapamycin, phosphoinositide 3-kinase and cAMP response element-binding protein). Furthermore, ENF inhibited the phosphorylation of extracellular signal-regulated kinase and thereby downregulated melanogenesis. In conclusion, ENF inhibited melanogenesis by suppressing MITF, which controls TYRP-1/2 and TYR. These results suggested that ENF may be a natural resource that can inhibit excessive melanin expression by regulating various melanogenesis pathways.

Association between sleep quality and type of shift work in Korean firefighters.

Background: Shift work that interferes with normal sleep patterns, is known to be a cause of sleep disturbance and has been studied through various occupational groups. However, it is not known which shift type is better for sleep health. Methods: This study included 568 firefighters. Sleep quality was evaluated using Pittsburgh Sleep Quality Index. Sleep quality was categorized into 2 groups; good quality (≤ 5 points) and poor quality (≥ 6 points). Demographic variables, depression, anxiety, type of shift, and job were collected by self-reported questionnaires. The χ2 test, t-test, and multiple logistic regression analysis were used to evaluate the effect of shift type on the sleep quality of firefighters. Results: Three hundred thirty-seven firefighters (59.3%) have poor sleep quality. Compared to day workers, the odds ratios (ORs) of poor sleep quality were 2.169 (95% confidence interval: 1.137-4.134) in 6-day cycle, 2.161 (1.150-4.062) in 9-day cycle, 1.805 (1.087-2.997) in 21-day cycle, and 1.485 (0.718-3.069) in 3-day cycle. The ORs of poor sleep quality were 1.697(1.021-2.823) in fire suppression and 2.325 (1.213-4.455) in emergency medical service compared to administration. Conclusions: All shift work type except for the 3-day cycle was associated with poor sleep quality compared to day work.

Application of several machine learning algorithms for the prediction of afatinib treatment outcome in advanced-stage EGFR-mutated non-small-cell lung cancer.

BACKGROUND: The present study aimed to evaluate the performance of several machine learning (ML) algorithms in predicting 1-year afatinib continuation and 2-year survival after afatinib initiation and to identify the differences in survival outcomes between ML-classified strata. METHODS: Data that were also used in the RESET study were retrospectively collected from 16 hospitals in South Korea. A stratified random sampling method was applied to split the data into training and test sets (70:30 split ratio). Clinical information, such as age, sex, tumor stage, smoking, performance status, metastasis, type of metastasis, dose adjustment, and pathologic information on EGFR mutations were inputted. Training was performed using eight ML algorithms: logistic regression, decision tree, deep neural network, random forest, support vector machine, boosting, bagging, and the naïve Bayes classifier. The model performance was assessed based on sensitivity, specificity, and accuracy. Area under the receiver operator characteristic curve (AUC) was calculated and compared between the ML models using DeLong's test. A Kaplan-Meier (KM) curve was used to visualize the identified strata obtained from the ML models. RESULTS: No significant differences in the input variables were observed between the training and test datasets. The best-performing models were support vector machine in predicting 1-year afatinib continuation (AUC 0.626) and decision tree in 2-year survival after afatinib start (AUC 0.644), although the performances of the ML models were comparable and did not display any predictive roles. KM analysis and log-rank test revealed significant differences between the strata identified from the ML model (p < 0.001) in terms of both time-on-treatment (TOT) and overall survival (OS). CONCLUSION: The performances of ML models in our study found no discernible roles in predicting afatinib-related outcomes, although the identified strata revealed different TOT and OS in the KM analysis. This implies the strength of ML in predicting the survival outcome, as well as the limitation of electronic medical record-based variables in ML algorithms. Careful consideration of variable inclusion is likely to improve the general model performance.

Comparative analyses of occupational injuries among temporary agency worker and direct contract workers: Findings from the Korea Health Panel 2009-2018.

OBJECTIVES: Several studies have reported health or safety risk of temporary agency workers (TAW). Since most of the studies are just cross-sectional studies, we intended to identify the risk of occupational injury in TAW, using longitudinal study design. METHODS: The Korea Health Panel 2009-2018 data were used in the study. For the statistical analysis of this study, we used a panel logit model to identify the risk of occupational injury in TAW compared to direct contract workers (DCW). RESULTS: There was no significant difference in risk of occupational injury between TAW and DCW among the overall population (adjusted OR 0.920, 95% CI 0.600-1.411). However, there was a significant increase in occupational injury in women (adjusted OR 2.134, 95% CI 1.092-4.170) and the "19-34" age group (adjusted OR 2.744, 95% CI 1.103-6.825) of TAW. CONCLUSIONS: This study provides evidence for vulnerable groups such as women and younger age groups in the relationship between TAW and occupational injury.

Multicenter real-world data of patients harboring rare mutations other than EGFR or ALK in advanced or metastatic non-small cell lung cancer.

BACKGROUND: Studies on the application of targeted therapies for patients with non-small cell lung cancer (NSCLC) who harbor rare genetic mutations are ongoing. In the present study, we investigated the real-world data of NSCLC patients who harbor rare mutations. METHODS: We retrospectively analyzed patients with advanced or metastatic nonsquamous NSCLC aged >20 years with confirmed rare mutations (BRAF, ROS1, MET, RET, HER2, FGFR, and NTRK) from January 2015 to September 2020 at nine tertiary hospitals. In addition, we validated the lung cancer PCR panel kit in patients with confirmed mutations by NGS. RESULTS: Among 118 patients included, 88 received platinum-based chemotherapy as first-line chemotherapy. The progression-free survival of patients with BRAF, ERBB2, MET, RET, and ROS1 mutations was 10.9 months (95% confidence interval [CI]: 1.3-20.5), 5.3 months (95% CI: 3.0-7.5), 7.2 months (95% CI: 3.6-10.9), 11.4 months (95% CI: 9.2-13.6), and 10.0 months (95% CI: 3.7-16.4) respectively (p = 0.041). The median overall survival (OS) was not reached in patients with ROS1 mutations; however, in BRAF, ERBB2, MET, and RET mutant patients, median OS was 14.1 months (95% CI: 10.1-14.1), 34.5 months (95% CI: 13.2-36.9), 22.7 months (95% CI: 1.7-24.0), and 29.8 months (95% CI: 28.9-61.3), respectively (p = 0.006). Of the 27 tissue samples, 26 (96.3%) showed the same PCR panel kit result with NGS. CONCLUSIONS: First-line platinum-based chemotherapy showed durable benefit in patients with advanced or metastatic nonsquamous NSCLC harboring rare genetic mutation other than EGFR or ALK.

The relationship between working hours and lifestyle behaviors: Evidence from a population-based panel study in Korea.

OBJECTIVES: This study aimed to investigate the relationship between working hours and lifestyle behaviors using data from a large nationally representative panel survey. METHODS: We used the Korea Health Panel Study (KHPS) data from 2011 to 2014. Weekly working hours and lifestyle risk factors were assessed by questionnaires. Comparing to the reference group, the weekly working hours were 40 h per week, odds ratios and 95% confidence intervals for smoking status, alcohol consumption status, and regular exercise status of other weekly working hours groups (<40, 40, 41-52, and >52) were calculated, using generalized estimating equation models considering repeated measures. RESULTS: Our findings clearly showed a relationship between long working hours and unhealthy lifestyles, such as cigarette smoking, alcohol consumption, physical inactivity, and insufficient sleep. Additionally, weekly working hours are positively associated with the amount of smoking and drinking, and inversely associated with sleep duration among those who worked 40 h or more per week. CONCLUSION: Long working hours are associated with unhealthy lifestyles, such as cigarette smoking, alcohol consumption, physical inactivity, and insufficient sleep.

The complete chloroplast genome of Abeliophyllum distichum f. lilacinum Nakai (Oleaceae) from the Chungbuk Province, Korea.

The chloroplast genome of Abeliophyllum distichum f. lilacinum Nakai, classified to a monotypic in this genus, and an endemic species in Korea, was sequenced to understand the genetic differences among intraspecies and cultivars of A. distichum. The chloroplast genome length is 156,015 bp (GC ratio is 37.8%) and has a typical quadripartite structure: 86,779 bp large single copy (35.8%) and 17,828 bp small single copy (31.9%) regions separated by two 25,704 bp inverted repeat (43.2%) regions. The genome encodes for 133 genes (88 protein-coding genes, eight rRNAs, and 37 tRNAs). Six to 99 SNPs and seven to 18 INDEL regions (19 bp to 72 bp) were identified against available chloroplast genomes of A. distichum. Phylogenetic trees show that A. distichum f. lilacinum is clustered with the Dae Ryun cultivar which has a larger fruit body. Our analyses suggest additional research, such as Genotyping-By-Sequencing, for understanding relationship between morphology and genotype of A. distichum.

Prognostic Factors of Second-line Immune Checkpoint Inhibitors in Patients With Advanced-stage Non-Small Cell Lung Cancer: A Multicenter, Retrospective Study.

OBJECTIVES: Immune checkpoint inhibitors (ICIs) targeting the programmed cell death receptor-1 and its ligand have achieved impressive success in treating patients with advanced-stage non-small cell lung cancer (NSCLC) after failed first-line cytotoxic chemotherapy. However, knowledge on clinical biomarkers that could help select patients who will respond well to second-line ICI therapy is limited. PATIENTS AND METHODS: Medical records of patients with NSCLC treated with first-line platinum-based chemotherapy and subsequent second-line ICI were collected from 6 medical centers between January 2018 and June 2020. Clinical information, pathologic variables, and radiologic findings of the data collected were reviewed. The patients were followed up until the date of the last visit, the death of any cause, or the end of data recording (December 31, 2020). RESULTS: A total of 181 patients with NSCLC were treated with second-line ICI following first-line platinum-based doublet chemotherapy. The median progression-free survival was 2.0 months (interquartile range, 1.0 to 5.5 mo), and the median overall survival was 12.0 months (interquartile range, 6.0 to 20.0 mo). Low body mass index (BMI) was independently associated with progression-free survival (odds ratio [OR], 0.826; 95% confidence interval [CI], 0.723-0.945; P=0.005). Similarly, a low BMI (OR, 0.839; 95% CI, 0.740-0.952; P=0.005) and a high number of metastatic organs (OR, 1.682; 95% CI, 1.156-2.448; P=0.007) were independently associated with the overall survival after second-line ICI therapy. CONCLUSION: BMI and the number of metastatic sites were significantly associated with second-line ICI therapy outcomes in patients with NSCLC receiving first-line platinum-based chemotherapy.

Impact of Long Working Hours and Shift Work on Perceived Unmet Dental Need: A Panel Study.

This study investigates whether workers with long working hours as well as shift workers perceive higher unmet dental care needs, and whether there is a gender difference in the associations. We used the Korea Health Panel (2009, 2011-2014) involving 20,451 person-wave observations from 5567 individuals. Perceived unmet dental care needs was defined when the participants reported that they perceived a need for dental treatment or check-up but had failed to receive dental care services during the past year. Fixed effects logit models were applied to examine how changes in weekly working hours or shift work status were linked to changes in perceived unmet dental needs within each individual. Among participants, 15.9-24.7% reported perceived unmet dental needs and the most common reason was time scarcity. We found that long working hours (>52 h/week) was significantly associated with perceived unmet dental needs due to time scarcity in both men (OR = 1.42, 95% CI 1.13-1.78) and women (OR = 1.35, 95% CI 1.03-1.79) compared workers working 40-52 h per week. Shift work was also a significant risk factor, but only in women (OR = 1.57, 95% CI 1.06-2.32). These findings provide evidence for labor policies to reduce working hours in order to improve access to dental care services.

Afatinib as First-Line Treatment in Asian Patients with EGFR Mutation-Positive NSCLC: A Narrative Review of Real-World Evidence.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) are a standard of care in the first-line treatment of patients with EGFR mutation-positive metastatic non-small-cell lung cancer (NSCLC). EGFR mutations are relatively common in Asian patients with NSCLC, and there is an increasing number of studies supporting the effectiveness of the second-generation TKI afatinib in routine clinical practice in Asia. This article reviews these real-world studies investigating afatinib as first-line treatment for EGFR mutation-positive NSCLC in Asian patients. Evidence from real-world studies with afatinib in this patient population supports findings from randomized controlled trials (RCTs) showing that afatinib is associated with more favorable outcomes compared with the first-generation EGFR TKIs. The effectiveness of afatinib has also been shown in real-world studies in Asian patients with poor prognostic factors, who are often under-represented or excluded from RCTs, such as those with uncommon EGFR mutations, brain metastases, or poor performance status, and elderly patients. The tolerability profile of afatinib in the real-world setting reflects that seen in RCTs, with no new safety signals reported in real-world studies in Asian patients with EGFR mutation-positive NSCLC. Dose-modification strategies also seem to be effective in the real world, with results of the RealGido study, which included 44% Asian patients, confirming findings from prospective clinical trials showing that tolerability-guided afatinib dose modifications can reduce the incidence of adverse events without adversely affecting clinical outcomes. While further research, including clinical trial data, is needed, real-world data have also demonstrated the feasibility of sequential afatinib followed by the third-generation TKI osimertinib in T790M-positive EGFR mutation-positive patients, which showed longer overall survival. Together, these real-world results demonstrate the real-world clinical effectiveness of afatinib as first-line treatment for patients with EGFR mutation-positive NSCLC.

Some patients with non-small-cell lung cancer (NSCLC) have a mutation in the EGFR gene, whose normal function is to regulate cell division. The proportion of NSCLC patients with these EGFR mutations is particularly high in Asian populations. Treatment of patients with EGFR mutation-positive NSCLC has changed markedly in recent years following the development of drugs called EGFR tyrosine kinase inhibitors (TKIs). Several EGFR TKIs have been developed, and clinical trial data have shown that the second-generation TKI afatinib and the third-generation TKI osimertinib are more effective than the first-generation TKIs erlotinib and gefitinib. However, these clinical trials, known as randomized controlled trials (RCTs), are highly selective, and many patients, such as elderly patients or those in poor health and/or with underlying diseases, are excluded. Consequently, less is known about how well TKIs work in these patients. Therefore, other less-selective studies, known as observational or 'real-world' studies, are used to provide information on the safety and effectiveness of EGFR TKIs across all patient groups seen in the clinic, not just those included in RCTs. In this article, we review the real-world evidence for the TKI afatinib as a treatment for Asian patients with EGFR mutation-positive NSCLC. Evidence from these real-world studies confirms that afatinib is more effective than erlotinib and gefitinib in real-world patients in Asia. Importantly, the efficacy and safety of afatinib is seen in groups of Asian patients often excluded from clinical trials including the elderly, those with brain metastases, and frail patients or those with other underlying diseases. Importantly, the safety profile of afatinib was similar to that seen in RCTs, and no additional side effects were identified in real-world patients. Also, importantly, real-world studies show that side effects can be effectively controlled by reducing the dose of afatinib. Real-world studies have also been used to demonstrate the feasibility and effectiveness of the sequential use of EGFR TKIs, particularly in Asian patients.

Work-Fitness Evaluation for Shift Work Disorder.

Shift work disorder (SWD), which is characterized by insomnia and excessive sleepiness related with shift work, is one of the most common health problems in shift workers. Shift work disorder causes insomnia, fatigue, worse work performance, an increased likelihood of accidents, and a poor quality of life. In addition, SWD is associated with decreased productivity and increased economic costs. The correct management of SWD is important to prevent sleep disturbances and maintain work performance in shift workers. To diagnose and evaluate SWD, it is necessary to take detailed medical histories, assess the severity of sleep disturbances, and evaluate shift workers' sleep using a sleep diary and actigraphy. The work-fitness evaluation should include recommendations on how shift workers can reduce their sleep disturbances and increase work performance, as well as the assessment of work performance. This paper reviews previous research on the evaluation, diagnosis, and management of SWD and summarizes the work-fitness evaluation of SWD.

Occupational physical activity, not leisure-time physical activity, is associated with increased high-sensitivity C reactive protein levels.

OBJECTIVE: This study aims to explore the association between physical activity and high-sensitivity C reactive protein, based on different types of physical activity-occupational and leisure time. METHODS: Using cross-sectional data from the Korea National Health and Nutrition Examination Survey 2015-2018, we explored the association between different types of self-reported physical activity and high levels of high-sensitivity C reactive protein (>3 mg/L). We estimated the ORs for high-level high-sensitivity C reactive protein using multiple logistic regression models after adjusting for covariates from 12 970 eligible subjects (mean age 44.8). RESULTS: Compared with subjects who did not engage in moderate-to-vigorous level of occupational physical activity (OPA), the group that engaged in moderate-to-vigorous level of OPA showed a significantly high OR (1.32, 95% CI (1.03 to 1.69)), whereas the group that engaged in moderate-to-vigorous level of leisure-time physical activity (LPA) yielded a low OR (0.84, 95% CI (0.69 to 1.01)). The group that engaged in moderate-to-vigorous level of OPA but not LPA showed a significantly high OR (1.76, 95% CI (1.27 to 2.45)) compared with subjects who engaged in moderate-to-vigorous level of LPA but not in OPA. CONCLUSIONS: OPA is directly associated with high C reactive protein levels, suggesting that it increases the risk of inflammation.